Temperature-regulator system



Oct. 11, 1927.

WITNESSES:

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H. R. TROTTER TEMPERATURE REGULATOR SYSTEM Filed July 19, 1924 INVENTOR flew/y R. 770/ler ATTORNEY Patented a. 11,1927. r UNITED STATE v 1,645,263? PATENT OFFICE.

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TEMPERATURE-REGULATOR SYSTEM.

Application 11.1 July 19, 1924. Serial n wness.

My invention relates to regulators for dual drive exciter sets and particularly to a temperature regulation system therefor.

One object of my invention is to provide a temperature regulation system that shall return to a neutral position after each operationthereof. I

Another object of my invention is to provide a temperature regulation system that shall automatically restore itself to neutral position after the completion of each preetermined operation.

In the operation of large power stations, it is necessary to have a separately-driven Z5 exciter for the field windings of the turbo generators. Inasmuch as the continuity of the power output of such generators depends upon the current traversing their field windings being maintained continuously, it has been found necessary to provide both a. motor and a small turbine to 'ointly and severally drive the exciter set. 11 the event that the voltage of the motor falls below its rated value, a greater proportion of the exciter load is impressed upon the turbine, which, in turn, draws a greater amount of steam;

As a measure of economy, it has been found desirable to conduct theexhaust steam from such exciter turbines into a preheater for the feed water of the station boilers. This practice is so general that, in many power stations, the exhaust steam from the exciter turbines is depended upon-almost entirely as a source of thermal energy for the,

preheaters for the boiler feed water. In

such cases, it has been found necessary to increase the steam flow through the turbine in the event that the temperature of the feed water heater falls below a predetermined value.

' The present invention relates to a temperature regulation system for controlling the exciter turbine governor in accordance with the thermal conditions in the. feed water heater.

The single figure of: the accompanying drawings is a diagrammatic view of circuits and apparatus embodying my invention.

' My invention comprises,in general, a feed water heater 1 and an exciter steam turbine 2, the exhaust from which is conducted by a conduit or pipe line 3 to the feed water heater, and a temperature regulating system 4 for varying the tension on the turbine governor 5. i The turbineZ ismechanically 'tively. The motor 25 is connected to one sideof an exciter generator 6 and the other side of the latter is connected to a motor 7.

Thefeed Water heater 1 is, provided with a thermostat 8 that is connected by a conduit or pipe line 9 to a sylphon bellows or thermally-responsive device 11. The thermostat 8, pipe line 9 and syl hon device 11 are filled with an expansib e fluid such'as mercury or ether. One face of the sylphon device 11 is attached to a rod 12 that, in turn, is pivotally connected, as at 13, to a heating link 14:. One end of the link 14 is pivotally connected to' a .rod 15 and the other end'is pivotally connected to a rod 16 that constitutes a plunger for an electromagnet 17.

Therod 15 is pivotally connected to one end of a contact member 18, preferably in the form of a sealed tube containin a conducting fiuid 19, such as mercury, t e other end of the tube 18 being pivotally mounted on a base member 21. The contact member 18 is provided with pairs of recesses or .wells 22 and 23 adjacent to the opposite ends thereof. The middle ortion of the contact member 18 is bowed ownwardly, as at 24, to form a pool or reservoir for the mercury 19. The wells 22 and 23 are each connected to an electrical conductor that passes through the walls thereof'and engages the mercury therein. v

The wells 22 are connected in series with the armature of a motor 25 and the holdmagnet Winding 26 thereof, the latter two being connected in' parallel relation; Similarly, the recesses 23 are connected in circuit with the armature of the motor 25 and its field-magnet winding 27 Suitable limit switches 28 and 29 are placed in circuit with the field-magnet windings 26 and 27, respecgeared to a gear wheel 31 that isinternal y threaded and mounted on a worm screw shaft 32, that is ada ted to move at right-angles to the plane of t e. gear-wheel 31 when the latter is rotated. One end of the shaft 82 is connected to a spring 33 that, in turn, is connected to the governor 5 and controls the tension thereof. The other end ofthe shaft 32 is. keyed,- as at 32a, to an arm 34:.

One end of the arm 34 engages a oke member 35 that is pivotally mounts as at 36 for controlling the limit switches 28 and 29. The other end of the arm 34: en- 31% gages a yoke 37 on an; arm 38 pivoted, as at 89 to the base of a-rheostat or resistor 41. The rheostat 41 is" provided with a plurality of terminals 42 that are connected 1n series with each other between the terminals 43- and 44. The arm 38 is so positioned that it can move across the'faces of the several terminals 42, 43 and 44 and'effeet electrical connection thereto. Thepivot point 39 is connected by a conductor to one of the conductors ot a supply circuit 46.

The terminals 43 and 44 of the rheostat 41 are connected to terminals 47 and 48, respectively, of the electromagnet 17 The 3 electromagnet 17 is provided with a pair of o .positely wound coils 49 and 51 between w 'uch moves an armature 52 that is carried by the plunger 16. The coil 49 is connected in a circuit extending from one of the conductors of the supply circuit 46 to the terthe mercury 19 contained in the minal member 48, the terminal member 53, coil 49, terminal member 47, terminal member 43, terminals 42, arm 38, pivot 39 and conductor 45 to the other side-of the supply circuit 46. The coil 51 is connected to one of the conductors of the supply circuit 46 through the terminal '48, coi 51, terminal 54, terminal 44 of the rheostat 41, terminals 42, arm 38, (pivot 39 and conductor 45 to the other si e of the supply circuit 46.

Assumin Y that the temperature of the feed-water eater 1 drops below a predetermined value, the sylp on device 11 will contract carryin with itthe rod- 12. Movement of the r0 12 causes the link 14 to turn about the end of the rod 16 thereby raising the contact member 18. Upward movement of the contact member 18 causes P0 to overflow and connect the wells 22. A emcuit is thereu on established that extends from one of t e conductors of the supply circuit 46 through one of the wells 22, mercury 19, the other well 2'2, the armature of the motor 25, to the other conductor of the motor 46. At the same time, the field winding 26 is ener ed if the limit switch 28 is in its close osition and the motor 25 rotates in a re etermined direction.

Rotation o the motor 25 turns the earwheel .31, which in turn, moves the sha 32 Lo the Is as viewed in the drawing, causes the time may 'tudinal movement of the shaft 32 toarm 38 to turn about its pivot 39 a clockwise direction, thereby placing a larger number of terminals L2 in circuit with a winding 51 and a smaller number of terminals in a I.

circuit withthe winding 49. The change in resistance of the circuits including the coils 49 and 51 results in amagnetic unbalance in the electromagnet 17 and the coil 49 predominates over the coil 51 with the result that the armature 52 and the plunger 16 moves upwardly.

Upward movement of the plunger 16 causes the link 14 to pivot about the point 13, which operation moves the rod 15 downwardly and then tends to iestore the contact member 18 to its neutral position. At the same time, the increase in temperature in the thermostat 8 causes the sylphon device 11 to expand which motion is transmitted by the rod 12 to the fulcrum point 13 causing further downward movement of the right-hand end of the contact member 18.

When the contact member 18 again reaches its horizontal or neutral position the mercury 19 returns to the well 24 and interrupts the circuit between the wells 22 and, consequently, the circuit through the motor 25 i with the result that the latter comes to rest. The arts remain idle as long as the thermal ,con 'tion in the feed-water heater 1 remains undisturbed.

Assuming the feed-water heater 1 to reach too higha "temperature, the -sylphon device 11 expands and depresses contact member 18 until the mercury 19 makes an electrical connection between the wells 23 whereuponthe field-magnet winding 27 and the armature ofthe motor 25 are energized and the motor rotates in a direction opposite to that heretofore described.

Rotation of the motor 25 moves the shaft 32 to the right of the device, thereby reducing the tension on the governor 5 with aresultant reduction in the amount of steam flow in the turbine 2. At the same time,

the arm 38 is turned in acounter-clockwise direction thereby permitting the efi'ect of the coil. 51 tovplil'edominate over the 'efiect of the coil 49. en the magnetic force of the coil 51 sufiiciently predominates over that of the coil 49, the armature 52 and lunger 16 move downwardl thereby raising the right-hand end of t e contact member 18 into its horizontal or neutral position. The

circuit between the wells 23 is thereupon interru tedand the motor comes to rest provid the field-muasgnet windin not been previo y opened switch 29. The foregoing cycle of operaon automatically and indefimtely n accordance with the difierent. changes n the temperature of the feedwater heater.- .I .do not wish to be restricted to the specircuit has ythe limit 35 the contact device from a neutral to circuit completing positions, an means 'cific circuit-connections or arrangementv of rality of positions, a motor controlled by the contact device, thermo-responsive means under the control of the motor for moving" the contact device from a neutral position to circuit completing positions, and means responsive to the operation of the motor for returning the contact device to its neutral position.

2. In a system of control, a contact device for completing a circuit in any one of a plurality of positions, a motor controlled by the contact device, thermo-responsive means under the control of the motor for moving the contact device from a neutral position to circuit completing positions, and means comprising a differentially wound electromagnet responsive to the operation of the motor for returning the contact device to its neutral position.

3. In a system of control, a contact device for completing a circuit in any one of a plurality of positions, a motor controlled by the contact device, thermo-responsive means under the control of the motor for moving osition comprising an electromagnet and a floating link mechanism responsive to the operation of the motor for returning vice to itsneutral position.

4. In a system of control, a contact device for completing a circuit in any one of 4 a plurality of positions, a motor controlled the contact dcby the contact device. thermo-responsive means under the control of the motor for moving the contact device from a neutral position to circuit completing positions, and means comprising a multi-wound electro-- magnet and means for var ing the current traversing each of the win ings of the electromagnet in response to the operation of the motor for returning the contact. device to its neutral position, v

5. In a system of control, a contact device for completing acircuit in any one of a plurality of positions, a motor controlled by the contact device, thermo-responsive means under the control of the motorfor moving the contact device from-a neutral position to circuit completing positions, and means comprising a multi-wound electro magnet, a link mechanism, and a rheo stat for varying the current traversing each of the windings of the electromagnet in response to the operation of the motor for returning the contact device to its'neutral position.

In testimony whereof, I have hereunto subscribed my name this ninth day of July HENRY R. TROTTER. 

